Process of chain manufacture



March 17, 1931.

R. w. DULL PROCESS OF CHAIN MANUFACTURE 1925 3 Sheets-Sheet l Filed March 10 March 17, 1931. w DULL PROCESS OF CHAIN MANUFACTURE Filed March 10. 1925 C5 Sheets-Sheet 2 ITHIITI mnun i fan March 17, 1931. R. w. DULL 1,796,593

PROCESS OF CHAIN MANUFACTURE Filed March 19, 1925 3 Sheets-Sheet 3 1% wa/m %ja// Patented Mar. 17, 1931 p iuirsn STATES PATENT oFFicE.

RAYMOND W. BULL, OF CHICAGO, ILLINOIS, ASSIGNORTO LINK-BELT COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS PROCESS OF CHAIN MANUFACTURE Application filed March 10, 1925.

My invention relates to a process for making chain from a strip of metalstock and particularly to a process for the continuous making and the automatic assembling of the. links into a chain. The general object of my invention is to produce chain of the type d scribed in which hook and pintle tongues are stamped from the center of the link blank and the hook and pintle end bars are bent to produce a chain, each link of which consists of flat side bars, relatively cylindrical hook at the end, and a pintle at the other shaped for rotation within the hook of the link next adjacent. One object is to provide a process for producing chain of the type described with maximum cheapness and simplicity. Another object is to provide a process for stamping or severing the hook and pintle tongues from the center of the blank and for curling them and the end bars into finished hooks and pintles with a minimum strain upon the metal of the blank and a minimum weakening and distortion of the fibers of the metal.

()ther objects will appear from time to time in the course of the specification and claims.

1 illustrate my invention more or less diagrammatically in the accompanying drawings wherein- Figure 1 is a plan View of the strip of material operated upon;

Figure 2 is a. section along the line 22 of Figure 1;

Figure 3 is a bottom View of the strip;

Figure 4; is a skeleton side elevation of the punch and die;

Figure 5 is a longitudinal section of the punch and die;

Like parts are illustrated by like characters throughout the specification and drawings.

A is any suitable base having mounted thereupon the die block A secured thereto in any suitable manner.

'15 is any suitable strip of relatively resistant metal, upon which rest the individual die elements which are mounted in the die block, and which are secured thereto in any suitable manner.

The passage of the metal strip C over the die block is from right to left, as shown in Serial No. 14,413.

Figures 4 and 5. This ribbon or strip C of stock may be initially straightened and fed by any means not herein shown, being guidedinto the machine, for example, by the rollers C channeled as at C and slidably and rotatably mounted on the vertical pins C positioned at either side of the die blocks.

Any suitable means may be used for feed ing the stock into and for drawing the cunt pleted chain away from the space between die and punch by a step by step movement, the stock being advanced one step between each forming action .of the punch, and being moved forward at each step a distance equivalentto the length of the blank or space from which the individual links are formed.

E is any suitable punch element and E is a relatively resistant base or backing adapted to receive the individual punch elements which will later be described in detail.

The progressive affect of the cooperation of the punch and die elements is shown in Figures 1, 2 and 3, and for the sake of clarity the impressions on the blanks made by the individual elements will be shown in small letters corresponding to the capitals which indicate the punch or die elements making them.

At the first step the punch G shearing against the edge (i of the die member G shears the end of the future hook tongue from the opposed edge or end of the future pintle tongue. The pintle tongue remains flat in the plane of the stock but the outer length of the hook tongue is forced downw'ardly therefrom, and is sheared from the side bars for approximately two-thirds of its future length. The member G being rounded as atG crimps the outer end of the hook tongue g, in anticipation of the final rolling operation. Meanwhile the prick punches G indent the future corners of the side bars and hook bar of the completed link. The longitudinal scoring knives G score the upper surface of the blank, outlining the separation between the pintle tongue and the sidebar and the opposed sco in kn ves G similarly score the bottom of the blank.

hen the punch is withdrawn and the stock has moved forward another step the tongue 9 is positioned over the upwardly humped die member H. As the punch mem-' outline the separation between the un-' severed portion of the hook tongue 9 and the side bars.

At the next step, the punch thrusts the blank downwardly against the die member J and its inclined forward surface J completes the separation of the hook tongue, thrusting it still farther upwardly from the blank. Meanwhile the punch member J with its creasing bead J thrusts the pintle tongue against the forming surface J of the die element J and bends it into substantial perpendicularity to the stock.

At the next step the hook tongue and the hook end of the link are not further modified but the punch member K operating against the die member K at the same time rolls the pintle tongue into final position and crimps or bends the pintle cross bar downwardly from the plane of the stock. The pintle tongue and end bar are confined between and formed by the. substantially arcuate forming surface K on the punch K the downwardly inclined surface K on the die member K and the face K of the severing knife 1?.

' At the next step the blank is positioned upon the die member L and the hook end bar is bent or crimped against the die surface L by the opposed arcuate face L on the punch member K. Meanwhile the knife K severe the blank from the stock, preferably without any preliminary transverse scoring between links, and the rearward surface K of the knife member serve as a stop to limit the downward movement of the hook cross bar during its formation. The severed link is held firmly in position upon the die member L for example by the spring pads L 'which engage the side bars, and which are downwardly thrust for example by the spring L Preferably a pair of such pads are'used, or a pad or gripping member which engages and operates against both side bars.

The pintle end bar, which at the preceding step was completely formed, is not operated on by the punch or die, but it is surrounded by the hook tongue which is rolled about it by the punch member M with its ,arcuate forming surface M lhe die member M is provided with a more orless flattened or slightly arcuate upper surface M3 upon which the pintle bar rests. The inclined forward die surface M of the member M limits the downward or rearward movement of the hook end bar during the rolling of the hook and its rearward surface M limits the movement'of the end of the hook as it is formed, thus controlling the diameter of the cylinder thus produced.

At the next step the severed and partly formed link, its pintle now surrounded by the hook of the preceding link, is drawn forward with the chain, its side bars rest upon the downwardly and rearwardly inclined die member 0, being held firmly in position thereon, for example by the spring pads 0 compressed by the springs 0 Its hook is then rolled about the pintle of the succeeding link, as above described.

In the formationof the chain, I employ opposed inwardly slotted edge gripping yokes P depending from the punch block and postioned at any, suitable point along the strip, Since the side bars of the blank are not in any way crimped or deformed or severed until the pintle bar is operated on the moment of severance of the preceding blank from the stock, it may be positioned at any point along the stock. 1 illustrate it herein, however, as positioned adjacentthe second forming step.

I provide any suitable supporting member R along which the finished chain may be drawn. 1 do not herein illustrate any specific feeding means, since the details of the feeding means used form no part of the present invention, but it will be realized that I may provide any suitable means for drawing the chain step bystep away from the die block as the successive forming impacts take place and as the stock is forwardly fed between punch and die.

The use and operation of my invention are as follows:

I manufacture chain from a ribbon or strip of metal stock which is fed forwardly, step by step, between opposed punches and dies. The interval between the forward feeding movement need be only suflicient to permit the strip to-move forwardly through the press the length of one link.

In order to prevent interference between the stock and the punch or die at the time of such forward movement, I provide means for :1

lifting the entire strip of stock from the die and for suspending it between die and punch intermediate the forming impacts, and for giving it its forward movement when so suspended and out of contact with either punch or die.

In the process herein shown, I move the strip upwardly after each impact to a position sufficiently high above the die to enable the hook 9', when downwardly turned, to clear 1 the die member G as the stock is forwardly moved. At the sametime, the strip is positioned at such a distance below the punch as to permit-the-hook tongue 9 to clear all the punch elements even when it is bent to its luv position of maximum height above the stock. The yokes P, which engage the edges of the stock serve to lift the stock, and to hold it suspended while the stock is being forwardly fed. The adjustment screws P permit of minor variations in width of stock used, and enable the yokes to be adjusted with whatever accuracy is necessary.

The strip of stock C is fed into the space between the punch and dies, for example through the rollers C which are provided with a circumferential channel or groove of V-shaped cross section. The stock cannot be caught or jammed in the rollers, since the rollers rotate in response toforward movement of the stock and thus prevent any tendency of the stock to clamp between the rollers, the bottoms of the slots or channels of the rollers being preferably positioned sufficiently far apart to aermit a slight clearance. The rollers are vertically movable along the pins C and permit such upward and downward movement of the stock as normally takes place.

In the form of punch and die herein shown, the portions of the link which are forced out of the normal plane of the strip are all bent upwardly toward the punch, save for the initial downward movement of die tongue 9 and the lifting movement of the yokes P need thus be relativelyslight.

In the method and mechanism of chain formation herein described, the side bars of the links are not in any way deformed or bent until the step succeeding that in which the final severing of both hook tongues from theside bars is completed. This bending occurs, in the case of the pintle bar, at the step before the blank is severed, and in case of the hook bar at the step when the blank is severed. Thus throughout most of its excursion between punch and die the stock is straight edged, and can be easily and efficiently forwardly fed through the slotted yokes or guides P.

The strip of metal stock of which the links are formed is a fibrous material, and, though tough and hard, is relatively yielding to impacts parallel to the grain of its fibers and is likely to tear along the line of the fibers, if weakened therealong. Thus it is necessary not only to render easy the severing of the parts which have to be severed, and to make this severing possible without a damaging distortion of the material, but also to limit the severing and to counteract the tendency for further and unintended tearing or severing, either during manufacture or during the later use of the chain. To make the severing easy, some of the parts to be severed are initially scored. To prevent unintended tearing, the lines of score are terminated by creases or indentations which modify the normal fibrous structure of the material, and

which prevent the formation of lines and angles of weakness and cleavage.

The successive steps of the operation may be summarized as follows:

First step.The top of the stock is prick shown in the drawings as about two-thirds,

of its length. The pintle bar is left in the plane of the stock and is not severed but scored both on the top and bottom by the scores 9 g which outline the separation between the pintle bar and the side bars.

Second atep.-The hook tongue g is thrown upwardly from the stock, although it is not further severed from the side bars. The separation between the unsevered portion of the tongue and the side bars is outlined on the top and bottom by the scores [L4 if. The pintle tongue 7a is severed from the side bars and up "ardly bent about the creasing bead H. forming the crease it in the stock.

I 715ml step-The hook tongue is now completely severed from the side bars, being sheared along the scores li it clear back to the prick punch marks g The pintle tongue is thrown upwardly about the creasing bead J into substantial perpendicularity to the stock.

Fourth step.-At this step the hook tongue and end bar are not operated on, but the pintle tongue is bent into final position and at the same time and by the same action the whole pintle bar is bent downwardly from the plane of the stock into its final position.

Fifi/i step.-The blank, with its pintle end completed, is now severed from the stock. The spring pads L engage the side bars and hold the blank in position. The book end bar is bent substantially into final. shape and the hook tongue is thrown still further around, or higher from the stock. The COIH'.

pleted pintle end is surrounded by the hook tongue of the precedingly severed link.

Simth step.iit this step the uncoinpleted link, which was at the preceding step joined to the chain, and drawn forwardly with it, is positioned on a slightly roarwardly inclined die member, being clamped thereon by the spring pads 0 The hook tongue is a then rolled about the pintle of the succeeding link into its final cylindrical form, and. the link is thus completed.

In the tools herein described I employ massive robust punch and die elements which are not rapidly worn and can be used for relatively long periods without replacement.

ldil

Taking the members from right to left of Figure 5, the prick punch points are durable. The punch G is a massive member and exerts a shearing action against the edge G of die'G The die G is a massive block and the shearing action is practically the easiest and least wearing type of action on the opposed elements. The die H is a massive member with no sharp edges or corners to wear off, as is the die member J. The creasing beads H J are not subjected to particular wear. The wear on the knife K is reduced by giving it a shearing action against the opposed punch- The various arcuate forming members are not particularly subject to wear. Thus I have developed a peculiarly robust and long lived set of tools.

It will be understood that whereas I have shown a practical process that I do not Wish to limit myself strictly to the specific details herein described and shown. I wish my description and drawings to be taken as in a broad sense illustrative rather than as limiting meto the specific showing.

I claim: v

1. The process of making, -irom a contit ous strip of sheet metal stock, chain having links comprising side bars, end bars, and hook and pintle tongues, which consists in initially indenting the inner. corners of the hook tongue and side bars, scoring the line of separation between the pintle tongue and the side bars, and downwardly bending the outer end of the hook tongue from the side bars along part of its length, and crimping'the outer end of the hook tongue; then shearing the pintle tongue from the side bars along said scores, bending it upwardly from the link, and creasing the insideor" the bend of the pintle tongue along the end bar, and scoring the lines of separation between the sid vbars and the unsevered nor-tion or" the hook i tongue, and upwardly bending the severed portion of the hook tongue, from the link; then com aletin the se )aration of the hook I ton ue alon said lines or score and bendin b b I. I l D it Iarther upwardly :rom the link and further bending and creasing the pintle tongue then bendin' the pintle end bar downwardl from 23 L the plane or" the link and rolling the pintle tongue into final position; then crimping the hook end bar downwardly from the plane of the link and further bending the hook tongue upwardly from the link andsevering the link from the stock; and rolling the hook tongue of the preceding link about the pintle end bar of the severed link substantially simultaneously with the severing. V

2. The process oi making, from a continuous strip of sheet metal stock, chain having links comprising side bars, end bars, and hook and pintletongues, whicn consists ininitially scoring the line of separation between the pintle tongue and the side bars, and bending the outer end or the hook tongue from'the separation ofthehook tongue along said lines of score and bending it farth r from the link and further bending and creasing the pintle tongue; then bending the pintle end bar from the plane of the link and rolling the pintle tongue into final position; then crimping the hook end bar from the plane of the link and further bending the hook tongue from the link and severing the link from the stock; and rolling the hook tongue of the preceding link about the pintle end bar of the severed link substantially simultaneously with said so erlng. i

3. The process o making, "from a continuous strip of sheet metal stock, chain having links comprising side bars, end bars, and hook and pintle tongues, which consists in first separating the outer end of the hook tongue from the link and scoring the lines of separation between the pintle tongue and the side bars; and indenting the innercorners of the hook tongue side bars, then bending the pintle tongue and scoring the lines of separation between the unsevered portion o1 the hook tongue and the side bars,'then completing the separation of the hook tongue from the side bars; then bending the pintle tongue and the end bar into final shape; then severing the link, with the hook still unformed, and subsequently curling the hook "tongue about the pintle ot' the succeedingly severed link.

4. The process of making, from a continuous strip of sheet metal stock, chain having links comprising side bars, end bars, and hook and pintle tongues, which consists in first separating the outer end of the hook tongue from the link and scoring the lines of separation between the pintle tongue and the side bars; then bending the pintle tongue and creasing the inside of the bend, and scoring the lines of separation between the unsevered portion of the hook tongue and the side bars, then completing the separation or" the hook tongue from'the sidebars; then bending the pintle tongue and the end bar into final shape; then severing the link, with the hook still unformed, and subsequently curling the. hook tongue about the pintle ofthe succeedingly severed link.

Signed at Chicago, county of Cook, and State of Illinois, this 6th day of hiarch, 1925.

RAYMOND N. D YT iAlJ. 

